Method of and means for separating desired from undesired electric currents



LSQQZS E. G. GAGE METHOD OF AND MEANS FOR SEPARATING DESIRED FROM UNDESIRED ELECTRIC CURRENTS origihal Filed April 20, 1921 2 Sheets -Sheet 1 INVEAIITOR Edward, G. Gage Br ,flWM UL ATTORNEY Aqg. 18.1925. 1,550,023

E. G. GAGE I METHOD OF AND MEANS FOR SEPARATING DESIRED FROM UNDESIRED ELECTRIC CURRENTS Original Filed April 20, 1921 2 Sheets-Sheet 2 ALLAH llLlLALA Hun huAuunAhAl-Hu W v Mr V v vvv v vv v iihnuuunnuniuuniuuuuu Auuuuuuu INVENTOR Edward 6'. Gaye Arm/um Patented Aug. l8, 19,25.

. UNITED stares PATENT OFFICE.

' EDWARD ecnon, on nn oo xnvn, NEW Yonx.

i v i o I METHOD OF A ND HEARS FOB SEPABATING DESIRED FROM UNDESJ 'BED ELECTRIC cunnnms.

Application filed A ril 20, 1921, Serial no. 463,072; Renewed September 12, 1924.

To all whom it may concern:

Be it known that I, EDWARD-G. GAGE, ,a citizen of the United States, and-resident of New York City, borough' of Brookl n, in

the county of Kings and State 0 New York, have invented certain new and useful Improvements in Methods of and Means for Separating Desired from Undesired Electric *Gurrents, of-which the following is a speci- 0 fication;

In the art of radio telegraphy and telephony currents in the atmosphere frequently interfere with the reception of signals desired in the receivers or'indicators of receiving sets. Under some conditions natural disturbances in the atmosphere, known as atmospherics or static, strays. etc., i interfere with the reception in receiving instruments of the desired signals transmitted from sending instruments. Also in the art of line wire communication, such as telegraph and telephone lines, disturbing influenc'es are sometimes present in the circuit -'.of a'lower frequency than the currents desired for the proper operation of receiving instruments.

An object of my invention is to separatev desired from' undesired currents at a receiving instrument, or, in other words, to eliminate from the receiver the disturbances produced by the undesired currentsand to permit the desired currents only to usefully affect the receiving instrument or telephone receiver.

In carrying out my invention I provide means interposed inthe circuit between the receiver and the collector or antenna to cancel low frequency currents that may'arrive in the collector or lineof a radio cir -fl cuit, or the line circuit of a telegraph or telephone system, and to utilize in the 'receiver only currents other than low frequency, or,1in -other words, where it is desi ed to receive currents otherFthan irregular 0 low frequency the latter are el minated or annulled before they can afiect'lthe .receiver. 'When low group' frequency is referred to herein the term is intended to 1nclude irregular impulses.

"In carrying out myinventiorrinforms iI- lustratedin the accompanyingdrawmgSigI provide two instruments used in conjunc tionfin. a circuit between a. receiverand'a" collector gr line, in one'of whlch instru-f-inrents currents of both high. and irregular or low frequency are reproduced and in the other of which instruments currents of low frequency only are reproduced, the said low frequency currents opposing one another whereby the low frequency currents are cancelled by their opposition, and as there is little or no opposition in said instruments to the high requency currents, the latter only are effective in the receiver as the desired cu'rrents. The instruments referred to, include transformers having their primary windings in circuit to receive impulses from the collector or line through suitable .instru'' mentalities, the secondaries of said transformers also, being in circuit and including means-to transmit currents for the receiver, preferably by means of amplifier devices, said transformers being provlded with movable iron cores operatedat different speeds. The speed of renewal ofone transformer core being faster than the other will reproduce currents of both high and low free quency, while the speed of thecore of the latter transformer-being less will reproduce low frequency currents only, with'the re sult that the low frequency currents in said I transformers .will cancel, permitting onl.

the high frequency currents usefully to, a

feet the receiver.

Reference is. to be had to the accompanyv mg drawings forming part hereof wherelm Flgure- 1 is adiagrammatlc view of a radio receiving system-embodying my invention; Figs. 2 and 3 are enlarged sectional detail views of the aforesaid transformers;

Figs. 4, 5, and 6 are'dia'grams illustrating graphically the method of separating desired from undesired currents. A receiving circuit is indicated at 1, which may be an antenna or collector 'of any suitable character well known in the radio art,

or-"the line of a telegraph or telephone circuit, shown used in connection with a we uum tube amplifier lndlcated generallyat 2 for amplifying received signals, the circuits of "which include a transformer 3 in the inputv circuit and a transformer .4 in theoutput circuit, said circuits including electrical sources 5, 6, and tuning condensers 7 8, in an, ordinary manner.--- WhileI have illustrated the/foregoing circuits as capable of use inico'nnection with my improvements it will be understood that the latter are not HEISSUED limited to use with such circuits. Included in the input circuit 9 of the secondary 4 of transformer 4 are the primary windings 10, 11, of two transformers 10 and 11, which primaries are shown in series. Included in circuit 9 a condenser 12 is shown which may be a variable air condenser. The secondary windings 10 11", of transformers 10 and 11, are included in opposition in'output circuit 13, one part of which circuit includes the primary winding 14* of a repeating coil 1 1. The windings of the trans formers 10 and 11 are shown on non-magnetic tubes 10, 11, respectively, and at 15', 16, are cores; preferably of iron, to be magnetized within the windings of said transformers. Across the secondary of said repeating coil is the small condenser 14 which act as a short circuit for any currents of radio frequency that might otherwise affect the vacuum tube 36.

Th cores 15, 16 may be in the form of endless iron wires, the core 15 being mounted upon pulleys 17 18, and the cores 16 being mounted upon pulleys 19, 20, which pulleys may be pivotally supported in. any suitable manner, whereby the cores may travel through the corresponding tubes 10, 11. Said pulleys may be rotated in any suitable manner. 1 have shown a pulley 21 that is connected to pulley 17 and receives a belt 22 from a drive pulley 23 to be operated by any suitable means, such as by an electric motor 24. A pulley 25 attached to pulley 19 receives belt 26 from a pulley 27 that may be operated in any suitable manner, as by an electric motor 28. Said pulleys may be operated manually. Assuming that motors 24 and 28 operate at similar constant speeds, and that pulley 21 is of greater diameter than pulley 25, it will be apparent that pulleys 17, 18 and core 15 will operate slower than pulleys 19, 20 and core 16. A magnet 29 is located adjacent to transformer 10 to maintain a constant magnetizing force on core-15 within transformer 10, and a magnet 30 is located adjacent to transformer 11 to maintain a constant magnetizing force upon core 16 within said transformer. Magnets 29, 30 are permanent magnets, and their magnetizing force respecting cores 15, 16,

, may be varied in any desired manner. Magnet 29 is shown in the form of an electromagnet having a winding 29 on core 29 said winding being in a circuit 31 including battery 32, a resistance 33 and a movable contact 34 operative with said resistance,

which contact 34 may be moved as required to-vary the magnetization of core 29?. Magnet 30 is shown as a permanent magnet movably supported at 30 and having a member 35 for manually operating the magnet to vary its roximity to core 16. The magnetizing orce of the magnets 29, 30, may be varied at will by adjusting contact3 1 or magnet 30, as may be required. As an example of the speed ratios of the two transformer cores, which resemble magnetic detectors, T have found that for eliminating irregular or low group frequencies below 200 per second, and receiving a signal of say, from 200 to 2,000 per second, a speed of one foot in five minutes is suitable for the slowly renewed core 15, and one foot in two seconds is suitable for the rapidly renewed core 16. It is important that the constants of both transformers be made nearly the same in order to obtain effective cancellation of impulses which affect both alike. A convenient size for the cores of the transformer in eliminating atmospherics or 37, 38. The input circuit 36 of amplifier 36 includes Winding 14; of amplifier coil 14, and the output 36 of said amplifier includes a receiver 39, such as a telephone receiver or current indicator.

The cores 15, 16 are continuously operated at substantially constant but different speeds when signals are to be received. A train of impulses arriving at the antenna or line 1 are transferred by means of the .radio frequency amplifier 2 to the primary windings 10, 11, of transformers 10,11, hence affect the secondary windings 10 11", of said transformers. Assuming that the impulses received in primary windings 10*, 11 include currents of low group frequency and currents of high group frequency, the low group frequency currents being in opposition in the windings 10, 11 will cancel one another or be eliminated and the currents of high group frequenc 'only will affect the repeating coil14 and e transmitted through amplifier 36 and the circuits 36" and 36 to receiver or indicator'39. The cancellation of the low group frequency current is caused by the action of the iron in the cores of the transformers 10 and 11, and by reason of the cores 15, 16 operating at different speeds, because the magnetizing forces exert strains on the molecules of the moving cores, hence the rapidity with which the molecules of the fast moving core are restored to normal and renewed when affected by the high frequency wave trains in transformer 11 diflers from the effect of the low frequency current in both transformers 10 and 11. I have ascertained iii the practice of my invention that a transformer, organized in the manner described, with its core being renewed w to a low than to a high group frequency,

fcated by the receiver'orindicator regardless I of what low frequency currents may at the 5 same time be received in the antenna or line 5 .and that such a transformer with rapidly renewed core not only responds to very high group frequency that ails to actuate such a transformer with slow moving core but fails to respond as energetically to a slow as to a high group frequency, although the last named transformer also responds to low group frequencies. Since both transformers respond to low group frequencies and since the'transformer having the slower moving core does not respond to the-high group frequencies (but the transformer havmg the faster moving core does respond to high group frequencies), it will be understood that, as before stated, the low group frequencies being in opposition in the cir-' cuits of the secondaries of the two transformers, oppose one another and are cancelled, thereby permitting only the high group frequencies to pass from the transformer having the faster renewable core to the receiver or indicator. 39. High group frequencies do not appear in the secondary 10 of the slowly operating transformer 10 because that portion of the iron in the transformer-core 15 is rendered inoperative to high group frequencies by fatigue. One transformer does not res frequency because -of' t 'e' suppressing or fatiguingeifect of the high group frequency on the core, still it is able to respond to low group frequency .in the absence of such suppressing or fatiguing effect In other words,

the high does not entirely disable the slow transformer. I assume that the outside only of the cores is affected by the high .group frequency. leaving the inside portion to re spond to the low group frequency. Bythe means described I am. enabled to select for the receiver or indicator; the desired currents'and to eliminate the undesired currents received together at the antenna or collector. In case no high frequency currents are received by. the apparatus, nothing will" be showmin' the receiver or indicator because the low frequency currents received by the apparatus will be cancelled. If there is high frequency'currentthat will be indicircuit.

Whilel have referred tolow frequency currents-it will beunderstood that similar eifectsoccurwithregard to currents of ir- Bb regular grouping or amplitude, since. they regarding low frequency currents; The refwill be cancelled in likemanner explained erence to high frequency currents I have made, means. desired currents as distinguished from undesired, such as low or ir'- regular group .frequency currents.

'scri ed in receiving currents 0 low frequency.

end-to high group derstood that the windings 10, 11", may

be in the same direction and that the polarity of magnets 29 and 30 may be reversed with respect to each other.

InFigs. 4, 5, and 6 Ihave illustrated gra' hically the 'efi'ectof the ap aratus dehigh and Fig. 4 represents graphically, without interference, the letter V as-received on an antenna from a radio transmitter and transferred by means of amplifier 2 to transformers 10 and 11. Said figure'indicates the acti on of such a series of impulses on each instrument alone and the result in a telephone, such as receiver 39, of the combination of these impulses. In Fig. 4, a indicates, currents of high group frequency in transformer 11, and corresponds exactly with the transmitted group frequency. b in Fig. 4

indicates the same signal as received by transfe'rmer 10, and illustrates only the first lmpulse of the train, in reverse direction from that 1n transformer 11.- There is,'also,

'a current of very small amplitude following the first impulse, due to fatigue of the action of transformer 10. a in Fig. 4 indicates the resultant or algebraic sum of these two opposed currents in transformers 1'0 and 11, I

and indicates a train of impulses similarto the original series sent out by' the transmitter, but .minus the first im ulse in, the train, and of slightly-decrease amplitude, causedby the partial cancellation of the sig-' nal due to partial operation of transformer 10 with respect to the high group frequency.

In- Fig. 5 are represented two wave trains one ofhighgroup frequency, and one of group frequency having the;

low, the low greater amplitude. At (5 in Fig. 5 is represented both high and low group frequencies (signals) present in. the secondary circuit of transformer 11", and e represents the currents in transformer 10. It will be noted that only the low group frequency 0 'is present in transformer "10 while both high and low group frequencies are present in transformer 11. It will also be noted'that the direction of current flow ,of thejlow group frequency-e in transformer 10 is opposite to-and in phase 'with'fithat in transformer 11 as shown by their relative positions on a-zeroline. At f in Fig. 5 is repre-. sented the resultant or desired current after group frequency only remaining.

.the low group frequencies in transformers Fig. 6 illustrates a train of signal impulses arriving at the antenna or collector and transferred therefrom by means of the radio frequency amplifier 2 and the circuits associated therewith to the primary circuit windings 10 11 of the transformers 10, ll, hence, to the secondary circuits thereof which are in series. At 9 in Fig. 6 is represented both desired and undesired currents as they are present in the circuits referred to while at h in Fig, 6 is represented currents in the secondary of transformer 10, the resultant current present in the secondaries of transformers 10 and 11 being represented at i in Fig. 6, after the currents have been opposed in said secondaries by reason of the direction of the windings or reversal of polarity of the magnets 29 and 30. In said figure the desired currents are represented by a regular'train of waves of high group frequency as sent out by a radio transmitter, the undesired currents being represented by a train of irregular waves as indicated at it, such as produced by atmospheric strays, both of such currents being represented at 9.

Having now described my invention, What I claim is 1, The method of separating desired audio frequency currents from undesired audio frequency currentsfln a circuit including transformers and a radio frequency amplifier consisting in passing desired and undesired currents through the input and output circuits ofa radio frequency amplifier, passing said currents through a plurality of transformers having cores, and causing separation of,the desired from the undesired currents in the cores of said.

transformers. v

2. The method of separating desired audio frequency currents from undesired audio frequency currents in a circuit'including transformers having cores consisting in causing said undesired currents to-energize the input circuits of said transformers in opposition, and causing the desired currents to de-energize one of said transformers by a signal frequency higher than the frequency of the undesired currents. c

4. The method of separating desired causing said currents simultaneously to flowthrough the primaries of a plurality of transformers and causing separation of the desired from the undesired currents in the v cores of said transformers.

5. The method of separating desired audio frequency currents from undesired audio frequency currents in a circuit including transformers having cores consisting in causing said currents simultaneously to flow through the primaries of a plurality of transformers, causing separation of the desired from the undesired currents in the cores of said transformers, and causing the desired current to affect the circuit of a receiver.

6. Means for separating'desired from undesired electric currents comprising a plurality of instruments having a common circuit to simultaneously receive said currents, said instruments having moving parts to cause cancellation in said instruments of said undesired currents by fatigue of one of the instruments, anda circuit from said instruments to receive the uncancelledcurrents.

7. Means for separatingdesired from undesired electric currents comprising a plurality of instruments having a common circuit to simultaneously receive said currents, said instruments havlng moving parts to cause cancellation in sald instruments of said undesired currents by fati ue of one of the instruments, and a circuit rom said 1nstruments to receive the uncancelled currents, an amplifying coil in said circuit, and a receiver in circuit with a winding of said coil r 8; Means for separating desired from undesired electric currents comprising a plurality of instruments having a circuit to simultaneously receive said currents, movable parts for said instruments, means to impart to said arts different magnetic excitations,

and a circuit from said instruments to receive desired currents therefrom.

9. Means'for separating desired from undesired electric currents comprising aplurality of instruments having a circuit to si-" multaneously receive said currents,-movable parts for. said lnstruments, means to impart to said parts different magnetic excitations,

simultaneously receive said currents, means to differentially energize said instruments magnetically, means to cause cancellation in said instruments of said undesired .cur-

rents, and a circuit from said instruments to receive the uncancelled currents.

11. Means for separating desired from undesired electric currents comprising a plurality of instruments having a common intransformers. 17. The combination of a receiving cirput circuit to simultaneously receive saidcurrents, said instruments having moving parts and means to difierentially magnetize said instruments to render one of said instruments capable 1 of becoming inoperative byfatigue, and means to receive desired currents from said instruments.

' 12. Means for separating desired fromundesired electric currents comprising a plurality of instruments having a common 1nputcircuit to simultaneously receive said currents, one of said instruments being subject to fatigue from currents of high frequency, to render said instrument inoperative, the other instrument not being subject to fatigue, an output circuit for said instruments, and means forindicating in the outputcircuit the difference in current strength in said instruments.

13. The combination of two instruments having 'windings in an input circuit and other windings in an output circuit, means to cause deslred and undesired currents to be received in the input circuit, movable cores vforsaid instruments, means to operate said cores at different speeds, and means to receive desired currents from said output circuit.

14. The combination of two instruments to cause desired and undesired currents to.

' .be received in the input circuit, movable cores for said instruments, means to operate said cores at diiferent speeds, means to receive desired currents from said output circuit,- and means to variably affect said instruments.

15. The combination of a plurality of transformers having their primary windings in an input circuit and their secondaries inan output circuit, movable cores for said transformers, means to operate said cores .at different speeds, and means to recelve desiredcurrentsfrom said output circuit.

' having windings in an input'circuit and .other windings in an output circuit, means to cause desired. and undesired currents to be received in the input circuit, movable.

cores for said instruments, means to operate said. cores. at diflerent speeds, means to re- 'ceive desired currents from said output cir- 'cuit, means toyariablyafiect said instruments, and means to'variably energize said secondaries in an output circuit, means to transmit. desired and undesired. currents from'the receiving circuit to said in ut circuit, movable parts for said trans ormers,

.means to operate said parts at different speeds,a rece1ver,. and meansto afliect said cuit.

- 18. The combination of a receiving circuit, a plurality of transformers having their primaries in an input circuit and their secondaries in an output circuit, means to transmit desired and undesired currents from the receiving circuit to said input circuit, movable parts for said transformers, means to operate said 'parts' at diiierent speeds, a receiver, means to aflect said receiver by currents from'said output circuit, and .means to variably energize said trans formers. v r

19. The combinatibn of a receiving circuit, a plurality of transformers having their primaries in an input circuitand their secondaries in an output circuit, means to transmit desired and undesired currents from the receiving circuit .to said input circuit, movable parts for said transformers, means to operate said parts at different .speeds, an amplifier having a coil included in said output circuit, a receivery'and a circuit for the receiver including the secondary winding of said amplifier.

20. The combination of-a receiving circuit, a plurality of transformers having I their primaries in an input circuit and their havmgw ndmgs 1n an 1nput c1rcu1t and secondaries in an outputcircuit, said input circuit including the secondary of a transformer, the primary of said transformer being in a circuit associated with said receiving circuit and including an amplifier, said first named transformers having movable cores, means tooperate said cores at different speeds, a receiver, and means to transmit desired currents from said. output circuit to said receiver. 4

21. The combination of'a receiving circuit, a plurality of transformers having their primaries in an input circuit and their receiver by currents from said output cirios secondariesv in an output circuit, said input circuit including the secondary of a transformer, the primary of said-transformer 16. The, combination of two instruments.

being in a circuit associated with said receiving circuit and including an amplifier,

said firstnamed transformers having movable cores, means to operate said cores at different 7 speeds, a receiver, and a'circu-it including the receiver and amplifying means, said circuit being associated with said output circuit.

22. The combination of a lreceiving'cir cuit, a plurality of transformers. having their primaries in an input circuit and their secondaries in anoutput circuit, said input circuit including the secondary'of a transing circuit and including an amplifier, said first named transformers having movable cores, means to operate said cores'at 'dlfier- I receiver and amplifying means, and a rey former, the primary ofsaid transformer bemg 1n a" circuit associated with said receivent speeds, a receiver, a circuit'including the peater coil having a secondary winding in the last named circuit anda primary Winds ing in said output circuit.

23. Means for separating desired from undesireC electric currents comprising a plurality of instruments having a-common input circuit to simultaneously receive said currents, one of said instruments adapted to receive a complete train of electric impulses and the other instrument adapted to receive an incomplete train of impulses, said instruments being connected in opposition, an output circuitassoc iated with said instruments,

- and means in the output circuit to utilize desired current from said instruments.

24. Means for. separating desired 'from undesired electric currents comprising a plurality of instruments having a common input circuit to simultaneously receive said currents, one of said instruments being subject to fatigue from currents of high frequency to render said instrument relatively inoperative, the oth er instrument being less subject to fatigue than the first named instrument, an output circuit for said instruments, and means in the output circuit for utilizing the desired current.

25. The method of separating desired from undesired electric currents consisting in amplifyin said currents, causing a portion of one 0 said currents to be suppressed by fatigue, placing said currents in opposition to cancel the initial impulse of the currents, and utilizing the remaining currents.

26. The method of separating desired from undesired electric currents consisting in receiving and amplifying interrupted currents, causing all except the initial impulse of one.of said amplified interrupted currents to' be suppressed by fatigue, plac- 40 ing said interrupted currents in opposition to cancel the initial impulse of the currents, causing said suppressed impulses to be restored between interruptions, and utilizing the remaining current as'desired current.

27. The method of separating desired from undesired electric currents consisting .in receiving and amplifying said currents of electrical impulses by causing certain impulses in the train tobe suppressed. by fatigue, ca'using said'suppressed impulses to, be restored after suppression, opposing said complete and incomplete trains of impulses to cancel undesiredicurrents, and utilizing the remaining currents as desired currents.

Signed at New York City, in the county of New York, and State of New York, this 18th day of April, A. D. 1921.

' EDWARD Gr. GAGE. 

